From owner-freebsd-stable@FreeBSD.ORG Thu Feb 11 15:00:17 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D5E2E1065696; Thu, 11 Feb 2010 15:00:17 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id A00FC8FC12; Thu, 11 Feb 2010 15:00:15 +0000 (UTC) Received: from odyssey.starpoint.kiev.ua (alpha-e.starpoint.kiev.ua [212.40.38.101]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id RAA25561; Thu, 11 Feb 2010 17:00:13 +0200 (EET) (envelope-from avg@icyb.net.ua) Message-ID: <4B741B7D.1030306@icyb.net.ua> Date: Thu, 11 Feb 2010 17:00:13 +0200 From: Andriy Gapon User-Agent: Thunderbird 2.0.0.23 (X11/20091206) MIME-Version: 1.0 To: alc@freebsd.org References: <4B72D94A.8030509@icyb.net.ua> <4B72E93C.80102@icyb.net.ua> <9bbcef731002101003r203f5189xf139700a0d48afa0@mail.gmail.com> <4B72F67F.4000209@icyb.net.ua> <9bbcef731002101026k5007075cqf97fc80404ac3fa7@mail.gmail.com> <4B72FC55.2090508@icyb.net.ua> <9bbcef731002101038r1ac04141t505216816489376f@mail.gmail.com> <20100210184623.GA78851@icarus.home.lan> In-Reply-To: X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org, Ivan Voras , Jeremy Chadwick Subject: Re: Strange problem with 8-stable, VMWare vSphere 4 & AMD CPUs (unexpected shutdowns) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Feb 2010 15:00:17 -0000 on 11/02/2010 06:37 Alan Cox said the following: > Here is what I know. Several of us, myself included, have been able to > reproduce either lockups or machine check exceptions when BOTH the machine > check driver and superpages are enabled on AMD family 10h processors. There > have been no reports of this problem on either Intel or earlier AMD > processors. Moreover, there is no evidence of instability in AMD family 10h > processors until the machine check driver is enabled. By default, FreeBSD > 8.0 enables superpages but disables the machine check driver. So, running > natively, i.e., without virtualization, you shouldn't experience a problem, > unless you explicitly enable the machine check driver. However, running on > top of a hypervisor, like vSphere 4, you might face a problem because the > hypervisor might enable machine check exceptions, regardless of what the > FreeBSD guest does. I really don't know whether vSphere 4 enables machine > check exception or not. If it does, then either you disable the use of > superpages in the FreeBSD guest, or you find a way to disable the machine > check driver in the hypervisor. I'd like to mention another possibility, just in case: machine check might be enabled/done by firmware (e.g. BIOS). This typically could be the case for high-end-ish/server systems. -- Andriy Gapon